The invention concerns a shift mechanism for motor vehicle transmissions with a selector lever supported in bearings in a housing, that can be pivoted about a longitudinal axle in the transverse direction and about a transverse axle in the longitudinal direction. Position indicating elements or sensors are arranged at the selector lever or at components moving with the selector lever on the one hand, and at components fixed to the housing on the other hand, in such a way that the sensors respond upon the approach to position indicating elements and transmit signals to a transmission control corresponding to the pivoted position of the selector lever.
U.S. Pat. No. 5,406,860 describes a transmission selector lever arrangement with a lever supported in bearings in a housing which can be pivoted in longitudinal and transverse direction within a guide slot, that is provided with a main slot and three subordinate slots parallel to the main slot and connected by transverse slots with the main slot. A sector component is supported in bearings, free to pivot, between a housing wall and the lever and is forced by a spring into a central position. By pivoting the lever within a transverse slot in the direction of a subordinate slot, the lever can be brought into engagement with the sector component so that both can be pivoted together in the longitudinal direction, as long as the particular subordinate slot permits. The lever and the sector component each carry a magnet. Hall effect sensors are arranged at the housing wall in such a way that when the lever is pivoted within a subordinate slot and upon the approach of the magnets to the Hall effect sensors, signals are generated that in each case correspond to the position of the lever. The sensor signals, in particular, can be used to determine in which subordinate slot the lever is located and which position it occupies within the subordinate slot. The known arrangement of the magnets and sensors, however, does not permit the detection of varying lever positions within any configuration of guide slots.
The object of the invention is seen as that of defining a shift mechanism of the aforementioned type that permits an automatic detection of the position of the selector lever in the longitudinal and transverse direction during any desired movement of the selector lever in the longitudinal or transverse direction.
According to the invention, the position indicating elements and the sensors are arranged in essentially two planes that are oriented approximately parallel to the planes that are defined, on the one hand by the pivoting path in the longitudinal direction, and on the other hand by the pivoting path in the transverse direction. This makes it possible to detect the position of the selector lever in the longitudinal direction as well as in the transverse direction. By a corresponding arrangement of position indicating elements on the one hand, and of sensors on the other hand, any desired position of the selector lever can be selected for a detection of the position in both directions of movement.
A preferred embodiment of the invention provides for the provision in the housing of a pivoting component that can be pivoted longitudinally about a transverse axle fixed to the housing. The pivoting component, in turn, contains a longitudinal axle about which the selector lever can be pivoted. Thereby the selector lever can be pivoted together with the pivoting component in the longitudinal direction and be pivoted relative to the pivoting component in the transverse direction.
Since thereby the pivoting component moves within a fixed pivoting path, that is defined by the transverse axle, a spacing from a housing wall extending perpendicular to the transverse axle remains constant. Thereby a constant spacing between the plane of the position indicating elements and the plane of the sensors can be maintained. Here there is a particular advantage in fastening at least one magnet to the pivoting component and to arrange at least one sensor in the region of the opposite housing wall in such a way that upon pivoting the pivoting component, the magnet enters the detection region of the sensor. The sensors applied here are preferably Hall effect sensors. In principle it would also be possible to fasten the Hall effect sensors to the pivoting component and the magnets as stationary parts to the housing, however, the routing of electrical lines to the stationary Hall effect sensors is simpler.
In order to be able to continuously detect the rotational position of the selector lever in the longitudinal direction, a preferred further development of the invention proposes that the rotational position of the selector lever be transmitted to a rotational transmitter. This can be performed, for example, by fastening a gear or a gear segment to the pivoting component which interacts with a further gear or gear segment, where the further gear or gear segment is connected by a shaft to a rotational transmitter. By appropriate dimensioning of the pitch circles of the gears a desired transmission ratio between the selector lever and the rotational transmitter can be achieved.
The application of a rotational transmitter is particularly advantageous if the shift mechanism is to be employed to transmit control signals for a vehicle drive with an infinitely variable transmission. Here, for example, the transmission ratio of the drive can be provided as input analogous to the position of the selector lever 14, which is detected by the rotational transmitter.
Preferably the rotational transmitter employed may be a non-contacting transmission, for example, a continuous rotational sensor with Hall effect element such as is offered, for example, by the company AB Electronics.
It is desirable that the operator feel at what point certain lever positions are reached or passed while the selector lever is being pivoted. For this purpose a preferred embodiment of the invention suggests that the pivoting components or the selector lever carry detent means that interact with detent elements formed fixed to the housing or on the pivoting component, in order to define detent positions during the pivoting of the selector lever in the longitudinal direction or in the transverse direction.
There is a particular advantage in the shift mechanism that can be applied to various applications, for example, for selector levers guided in different guide slots, where in any case minor, simple compliance measures must be taken. This permits the manufacture of shift mechanisms in relatively large volume and permits a reduction in manufacturing cost and a rational supply system. In order to attain these goals a preferred embodiment of the invention proposes that the detent elements fixed to the housing and/or the detent elements arranged on the pivoting component be configured on components that can be fastened to or interchanged with the housing or the pivoting component. Such components may, for example, be interchangeable plates with a detent scheme, for example, with one or more recesses in which a ball of the detent means engages. By means of the interchangeable longitudinal and transverse detents, a universally useful shift mechanism, also called shift unit, can be attained.
The detent means is preferably a ball pressure element, whose ball interacts with a detent element configured as a cam surface that may, for example, contain recesses and/or projections. The ball pressure element contains a spring-loaded ball, that can be depressed.
According to a preferred further embodiment of the invention, the housing contains a support component supported in bearings that can be pivoted about a longitudinal axle fixed to the housing which participates in the transverse pivoting movement of the selector lever relative to a driver. The support component carries at least one position indicating element, in particular a magnet, which intrudes during the pivoting of the support component into the detection region of at least one sensor fixed to the housing, preferably a Hall effect sensor.
A simple, preferred configuration of the driver is provided by a fork-shaped receptacle on the support component that engages a strap of the selector lever extending in the direction of the transverse axle which can be slid within the receptacle. This permits a pivoting of the selector lever in the longitudinal direction in which the strap is shifted in longitudinal direction within the fork-shaped receptacle, without any pivoting motion of the support component. However, if the selector lever is moved in transverse direction, the strap transmits the pivoting motion to the support component, and pivots this along with the selector lever.
A further particularly preferred embodiment of the invention, that makes it possible for the shift mechanism to comply with different applications, provides for at least one adapter element, that can be fastened to the housing and is interchangeable, on which at least one sensor is arranged, in particular a Hall effect sensor. For the particular applications in each case adapter elements can be employed, that are equipped variously, with differing sensor arrangements. The adapter elements can be mounted very simply on the housing, for example, by bolting or by engaging detents, and are easily interchangeable.
Preferably the adapter element may be configured as a circuit board or an integrated circuit, that carries further electrical components in addition to the sensors, for example, for the processing of sensor signals.